System of control for elevators



4 Sheets-Sheet 1 INVENTORJ 01 246 /4( 3415577" /%?040 J/Zzw June 7, 1932. c..w. BASSETT ET AL SYSTEM OF CONTROL FOR ELEVATORS Original Filed April 15. 1927 June 1932- c..w. BASSETT ET AL 1,362,291

SYSTEM OF CONTROL FOR ELEVATORS Original Filed April 15. 1927 4 Sheets-Sheet 2 INVEN TOR. CrM/J W. 24:55:77 #49040 J/ZWR June 1932- c. w. BASSETT ET AL SYSTEM OF CONTROL FOR ELEV'XTORS Original Filed April 15, 1927 4 Sheets-Sheet 3 June 1932. c. w. BASSETT ET AL 1,862,291

SYSTEM OF CONTROL FOR ELEVATORS Original Filed April 15. 1927 4 Sheets-Sheet 4 y 4% 1 ATTOR Patented June 7, 1932 CYRUS W. BASSETT AND HAROLD J. FEAR, i035 MONTCLAIB, NEW JERSEY, ASSIGNORS TO ELEVATOR SUPPLIEE COIYLPANY, INC., 013 HOBOKEN, NEYV SEE-E1, A. COBTPORA- TION OF NEW JERSEY SYSTEM OF CONTROL F01; ELEVATORS Original application filed April 15, 1927, Serial No. 184,082. Divided and this application filed. July 25,

for controlling the elevators to automatically start from a terminal station and stop at predetermined points, and to automatically start from each of said pointsf Another object is to provide parcel-carrying elevators which will automatically load or unload parcels or other material at such points.

Specifically one of the objects of the invention is to provide in connection with a parcel elevator (or dumbwaiter as it is sometimes called) a plurality of compartments so constructed and so controlled as to permit the loading and unloading of the compartments to occur automatically and in harmony and coordination with the control of the ele vator itself. In pursuance of this object the 'avention described herein discloses means whereby it is possible to cause an elevator having a plurality of parcel containing compartments to start automatically from a terminal station and stop automatically and successively at a plurality of intermediate stations, deposit the proper parcel or parcels at certain of said stations and also receive whatever parcels there may be for deposit at certain stations, and then return automatically to the terminal station with all of the parcels pickedup at the intermediate stations.

Other objects an d features of the invention reside in the specific construction, arrangement and combination of the parts and will become more apparent from an inspection of the following specification when read with reference to the accompanying drawings wherein like reference characters refer to like parts throughout the several views.

In the drawings Figure 1 shows a vertical Serial No. 295,187.

section through an elevator shaft in which an elevator of the preferred construction embodying this invention is suspended.

Figure 2 is an enlarged elevation view of a portion of the elevator car shown in Figure 1 and showing some of the operating mechanism mounted thereon.

Figure 3 is a vertical section showing a typical unloading chute and part of the operating mechanism therefor.

Figure 4 is a schematic diagram of the electrical signal and control circuits and parts entering into the preferred embodiment of the invention.

Figure 5 is a view of the operating linkage of a typical loading chute.

Figure6 is a detail view of some of the parts of Figure 2, taken at right angles thereto.

Referring to Figure 1 reference character 101 is used as a general designation for an elevator (dumbwaiter) car representative of the preferred type; As shown in this figure the car is suspended by means of a cable 102 passing around the sheave 103 and thence downwardly to a suitable drum (not shown) adapted to-be driven by the hoisting motor shown schematically at 1 in Figure 4. In the preferred construction as shown the car 101 is provided with a plurality of tilting walls or shelves indicated by dash lines 104, 105, 106, 107 and 108 are shown in Figure 1 as occupying their normal positions, in which position the shelves have a backward tilt away from the side 114 of the'elevator shaft, it being understood that side 114 is the front (that is, the free) side of the shaft. The upper shelf 104 is shown in Figure 1 as tilted forwardly, and with the car in the position shown in this figure the shelf is substantially on a line with the floor 115 of the chute 116 mounted in the front face 114 of the elevator shaft. 7

This chute 116, which may be considered as typical of the preferred type of unloading chutes placed at each unloading station along the elevator shaft, comprises essentially a suitable housing (preferably but not necessarily of sheet metal) having a sloping floor 115 of a smooth polished finish and, if desired, provided with rollers or other suitable means for facilitating the sliding or rolling of parcels or containers thereupon. The chute 116 is also provided with a shutter 117 normally closing the free passageway of the chute but capable of being raised to the position illustrated in this figure so as to permit passage of articles. In the preferred construction as shown the shutter 117 is mounted to swing about a pivot pin 118 journalled in a suitable bearing adjacent the chute 116. Suitable means for rocking the shutter 117 about its pivot 118 are provided and in the preferred form as illustrated comprise a link mechanism. consisting of a pair of links 119, 120, a pair of free pivot pins 121 and 122, a lever arm 123, a fixed pivot pin 124 and a plunger 125 pivoted to the lever arm 123 and adapted to be raised by suitable means, such as an electro-magnetic solenoid 16. With a construction of this kind it is apparent that energization of the solenoid 16 (which may be effected by control means hereinafter to be described) will produce a raising of shutter 117 from the position shown in dash lines in Figure 3 to the position shown in full lines therein, and that upon de-energization of the solenoid the consequent dropping of the plunger 125 will permit the shutter 117 to again assume its normal position, in which position, as suggested by the dash line, free egress of articles along the floor 115 of the chute is prevented. Similarly each of the unloading stations along the elevator shaft is equipped with an unloading chute preferably of similar construction.

In addition to the series of unloading chutes typified by chute 116 just described in detail, there is also a series of loading chutes similar to the one illustrated in Figures 1 and 5 and designated generally by reference character 130. As shown in Figure 5 the loading chutes are somewhat similar in construction to the unloading chutes, the principal difference being that the floor .131 of the loading chute tilts toward the elevator shaft rather than away from it for the obvious purpose of facilitating the ready sliding or rolling of an article or container, as 132a, into the car 101 when the latter is standing in proper position for reception of such an article. In the position shown in Figure 1 the car is not in such position as to receive articles from this loading chute 130 and the transmission of articles down this chute is prevented by the position of the shutter 132 as shown. When, however, the car 101 is in a position to receive articles from this loading chute 130, the shutter 132 may be raised about its pivot pin 133 to the position shown in Figure 5 by suitable mechanism, preferably of a similar construction to that illustrated in Figure 3 and just described in detail in connection with the operation of the unloading chute 116. As shown in Figure 5, this mechanism comprises links 134, 135 and 136, and plunger 137 associated with a solenoid (not shown) similar to solenoid 16.

In this connection it should be observed that due to the relative disposition of the links 120 and 123, and 135 and 136, the shutcannot be raised by exterior manipulation, but only by the movement of the plungers, as 125 and 137. Such movement occurs only upon energization of the proper solenoid, as 16, in the regular operation of the system, as will be explained.

In the preferred arrangement the control of the car is so arranged that the car when stopping opposite a particular. loading or unloading chute Will always stop in such a position that a certain pre-selected compartment will have its shelf on a line with the floor of that particular chute. That is to say, the control is so arranged that when car 101 stops for the deposit of articles down the unloading chute 116, the car will be stopped in the position shown in Figure 1, in which position the shelf 104 is exactly on a line with the floor 115 of the unloading chute. Similarly, carrying out the same scheme of operation, when the car 101 is stopped adjacent the loading chute 130 for the reception of articles from the latter chute, means are provided, and the control is so effected, that the car will stop with the shelf 104. exactly on a line with. the floor 131 of the loading chute 130. Similarly each of the other unloading chutes along the face 114 of the elevator shaft will have a corre' sponding compartment in the car 101 and the shelves of these corresponding compartments will always select their associated chutes. This selection takes place automati cally thru the instrumentalitv of the car control. means which effect the stopping of the car at exactly the prop-er point to brim? about this perfect alignment of each shelf with its corresponding chute. The control means for effectuating this result will be described hereinafter.

A detent lever 141 mounted on the side of the car serves to hold the rocker arm 140 its normal backwardly tilted position. as shown best in Figure 2. When it is desired to permit the rocker arm 140 of the shelf 104 to tilt forwardly. this detent lever 141 is knocked away from the outer end of the rocker arm 140 bv suitable means such as a denendinq' arm 143 mounted in proper pos tion for this purpose in the elevator shaft on a suitable supporting plate 144 and adapted when pushed in a clockwise direction to strike the lug 145 offset from the detent lever 141, as shown clearly in Figure 6. The

pivotally supported at the top and bottom of the elevator car 101 by means of bearing 147 and pin 148 respectively, as shown in Figure 1. This transversely moving cam 146 normally hangs in the position shown in phantom lines in Figure 2 but is capable of transverse movement to the left to the position shown in full lines in Figures 1 and 2, in which position it is in striking engagement with a roller 150 mounted on the depending arm 143. This transverse move ment of the cam 146 is effected by suitable means operated in synchronism with the operation of the car 101 and comprising in the preferred construction a: pair of links 151 and 152 and a plunger 153 adapted to be drawn into the solenoid 154 upon energization of the latter. With the construction just described it is apparent that the energization of the solenoid 154 will produce a transverse movement of the cam 146 into striking engagement with the roller 150, thereby pushing the depending arm 143 in a clockwise direction and against the offset lug 145, thereby rocking the detent lever 141 out from under the rocker arm 140 and permitting the latter to descend in a counter-clockwise 'direction to the forwardly tilting position to which position gravity or other suitable means tends to move it when loaded as soon as it is released from the restraint normally exercised upon it by the detent lever 141.

A so-called interlocking switch is shown at 160 as adapted by means of suitable link motion (such as that shown) and to be thrown to circuit-open position upon'the energization of solenoid 154, for a purpose hereinafter to be explained more fully. Similarly each of the chutes are equipped with switches (see switch 60, Figure 3) similar to switch 160 which are adapted to move to circuit-open position upon energization of the associated solenoid, such as 16, for a purpose to be described more fully hereinafter.

Having now described the principal mechanical parts of the system, the preferred electrical control means for effecting the automatic starting, running, stopping, loading and unloading will now be described, with particular reference to the detailed schematic diagram shown in Figure 4.

The hoisting motor for the car 101 is shown schematically at 1 in this figure. As shown by way of illustration of the preferred embodiment the motor is of a two-speed alternating current type having the three phases shown for each of two speeds designated as low speed and high speed. The direction of the motor rotation is controlled by means of the directional switches 2 and 3. all of which are normally opened and which are adapted to be selectively closed by means of the relays 2a and 3a. The switch 4 is shown controlling the feed to the motor 1, the feeds being provided with suitable time limit fuses as shown at 5. If desired for purposes of protection, a reverse phase relay 6 controlling the closing of the normally open contacts 6a. The relay 7 controls the three normally opened switches 7 a, 76 and 7 0 which close upon operation of the reverse phase relay 6. The current is introduced to the system by means of the line switch 8 and this current also serves to feed either one of the motor generator sets 9 and 10 which are provided for the purpose of converting the alternating current to direct current, it being advisable to use direct current for the control of the various relays and switches and other parts entering into the automatic operation of the system. If desired, a pilot lamp 11 may be inserted across the direct current line to indicate whether or not the direct current feed is alive. It is also desirable to have an additional feed line switch as 12 which may be mounted in a convenient location, as for instance, on a panel serving as a mounting plate for the control parts of the system about to be described. The circuit selecting commutators are shown at 13 and 14 and are provided for the purpose of governing the sequence of operation of the various electrical and electro-mechanical units which come into opermutator brushes. The preferred mechanical construction of the commutators is to have the brushes mounted on a carriage having an internal screw thread adapted to travel along a screw which is rotated by movement of the car 101. This mechanical construction of the commutator and driving means therefor is well known in the art of elevator signaling and further explanation is believed unnecessary here because of this, a very clear description of the details of this particular feature being shown in patent to Smalley and Reiners No. 826,752.

Connected in circuits passing thru the segments of the commutators 13 and 14 are a series of solenoids 15 to 24 which are the chute operating solenoids similar to the solenoid 16 described in connection with Figure 3. Also connected with segments on selector 14 are the, relays 25 to 34 inclusive which control the starting of the car at the proper points with respect to the location of the successive loading and unloading chutes. 35 represents the armature of a timing-motor which drives a set of successively operating switches 36 designated respectively by the characters 36a, 36b, 36c and 36d, these switches controlling the operation of the shutters in the chutes. the shelves in the car 101 and the resumption of the travel of the car. Relay 37 controls the cutting off of the timing motor after it has accomplished its functions. 38d represents a buzzer or suitable audible signal which is preferably provided to warn the attendant at the sending station of the approach of the car to that point, and is adapted to be operated upon closing of contacts 38a by relay 38?). Contacts 39 and 40 are contacts adapted to be bridged by the starting button 41 located in a convenient position at the sending station.

Reference character 42 designates a relay controlling three sets of contacts, as follows: The normally open contacts 42a in the circuit to the brake solenoid 42, the normally closed contacts 420 in the circuit to the starters button 41, and the normally open cont-acts 4261 in the circuit thru conductor 43' governing on difierent occasions the slow down relay 44, the speed change relay and the relay 37. The relay 44 in turn controls the normally open contacts 44a and the normally closed contacts 44b, the latter being in series with the relay 45. The relay 45 in turn controls the speed change switches 45a which govern the path of current thru the motor 1, thereby regulating the speed thereof. Relay 37 controls the cutting off of the timing motor 35, as above explained. Relay 46 is a relay interposed in a circuit which is completed at the point 47 when the car moves away from its terminal station and which remains in this closed condition until the return of the car to the terminal station, it being understood that the construction of the switch 4'? is such that it is physically moved to circuit closing position by the departure of the car. The result of this arrangement is that relay 46 remains energized and consequently contacts 46a and 460 remain closed at all times while the car is away from the terminal station.

The switches 48 to 57 inclusive are provided for the purpose of breaking the hoisting motor control circuits when it is desired to bring the car to a complete stop. These switches therefore are mounted in the proper positions in the elevator shaft so as to be operated successively by the car upon reaching these successive landings. The switches 59, 59 are overtravel limit switches placed at either end of the elevator shaft as a safety precaution. The switch 60 represented on the diagram represents the safety switches provided in connection with each of the load ing and unloading chutes and also provided in connection with the shaft door at the terminal station, these switches being so disposed as to assume closed position when the associated chutes or door, as the case may be, are in closed position, and move to circuitopen position upon movement of the associated chute or door to open position. 61 designates a so-called slack cable switch designed to move to open position when the cable becomes slack for any reason, such as a slipping of the car or of the hoisting mechanism.

Carrying thru a typical operation of the system let it be assumed that the line switches 8, 8a, 4 and 12 are all closed so that the power is available both for the hoisting of the car and for controlling of the automatically acting apparatus. With this assumption let it be supposed that the sender closes the circuit passing thru contacts 39 and 40 by operation of the starting button 41. This operation closes a circuit passing from line 62 thru conductor 63, contacts 40 and 39,11ormally closed sending station relay contacts 46?), strip 64 on a commutator 14, segment 65, (it being assumed that the commutator brushes bridge this segment when the car is at the sending station), conductor 66, relay 26, conductor 67, normally closed slack cable switch 61, the overtravel limit switches 59, normally closed door contacts 60 operated by closure of the elevator shaft door at the sending station, thru conductor 68 back to the other side of the line 69. Energization of the relay 26 thus produced causes closing of the contacts 26a, thereby completing a branch circuit branching from the conductor 67and 68 to the conductor 70 and thru the contacts 26a, contact 49, up directional relay 3a, thence back by way of conductor 71 and relay 42 to the line 62. Energization of relay 42 thus produced closes its contacts 42d, thereby completing a circuit thru the relay 45 governing the speed change switch 45a. The resulting operation of the speed change switch 45a opens the low speed connections and closes the high speed connections, thereby placing the motor 1 in readiness for high speed operation. At the same time energization of the up directional relay 3a causes closure of the up directional contacts 3 and the consequent operation of the motor 1 thru the high speed windings.

At the same time the energization of the relay 42 causes a closing of the normally open contacts 42a, thereby energizing the brake coil 42?), releasing the brake on the motor 1 and opening the contacts 420, thereby breaking the circuit passing thru conductor 63 if it has not already been broken at the starters button 41. The energization of the relay 42 also causes energization of the relay 37 in the circuit passing thru contacts 42d, contacts 85a and relay 37. Energiza'tion of relay 87 thus produced causes an opening of the normally closed contacts 3764, thereby preventing energization of the timing motor 35 so long as the relay 37 remains energized.

The energization of the hoisting motor 1 thus produced by the closure of circuit thru relay 3a causes the hoisting of the car at its high speed along the shaft and con sequent movement of the commutator brushes along the commutators 13 and 14. As the movement of the car brings the brushes to car is away fro-m the sending station (as a point on the commutator strip 77 designated by the character 75, a circuit is completed passing from the side 62 to the line thru conductor 76, strip 7 7, brush spanning segment 7 5, conductor 7 8, relay 44 and previously closed contacts 420? to the other side 69. Energization of the relay 44 thus produced causes the closure of contacts 44a, thereby forming a holding circuit for the relay 44 in shunt with the circuit just traced; and at the same time causes the opening of contacts 44?), thereby deenergizing the speed change relay 45. De-energizationof the speed change relay 45 thus efiected causes opera tion of the speed change switch 45a so as to shift the path of current to the hoisting motor 1 from the high speed connections to the low speed connections.

Further movement of the car brings it into engagement with the limit switch 49 previously described. Operation of the limit switch 49 causes an opening of the circuit passing thru the conductor 71 and the directional relay 3a, de-energizing the latter. De-energization of the relay 3a thus produced causes the opening of the circuit to the motor 1 at the switch points 3. At the same time the de-energization of the brake solenoid 42b in the same circuit permits application of the brake to the hoisting motor, thereby bringingthe car to a sudden stop. It is well to note in this connection that the deenergization of the relay 42 permits the con tacts 42c again to assume their normally j closed position. The position which the commutator brushes have reached at the time of the complete stop of the motor by the means just described is the position indicated by the location of the segment 7 9 and 80; in other words, as the car comes to a stop, commutator brushes are spanning segments 79 and 80.

The opening of the contacts 42d which occurred upon the breaking of the circuit j thru the conductor 71 results in the de-energization of relay 37 and the consequent resumption by the contacts 37a of their normally closed position. Inasmuch as the contacts 46 are closed at all times when the previously explained) a circuit is now made to the timing motor armature 35 passing thru the contacts 37a, 46a, armature 35 and back to the other side of the line. Energization of the timing motor 35 thus produced causes rotation of the shaft on which the switches 36 are mounted in staggered alignment. Rotation of the shaft of motor 35 thus effected therefore causes the successive closing of switches 36a to 36d. 7

Closure of switch 36a causes the energization of relay 81, which operates to'close a holdingcircuit for itself and also to'close contacts 815, thereby completing the circuit to chute solenoid 16 to raise the shutter 117 to the open position. Next in succession is the operation of relay 82 which thus forms its own holding circuit and also closes the contact 82?), thereby permitting the energization of solenoid 154 so as to permit the tilting of shelf 104 in the manner previously described to permit whatever articles there are on the shelf to slide or roll out at the landing adjacent the chute 116. Next in order is the energization of relay 83, which causes the de-energization of relays 81 and 82 and aiso the de-energizati0n of chute solenoid 16 and car solenoid 154. De-energization of chute solenoid 16 permits closing of shutter De-energization of car solenoid 154 allows the cam 146 and roller 150 to retire and the rocker arm 140 to become locked by the detent lever 141, the shelf (together with the arm 140) having previously returned to normal position upon dumping its contents. It alsopermits reclosing of safety switch 160. Next in order, the closure of switch 36dl causes the energization of relay 84 and the energization of relay 85, thereby opening contacts 85a. Energization of relay 84 again closes the contacts 84a in the shunt circuit about the starting button 41 and thereby closes thecircuit to the up directional relay 3a previously described in connection with the starting of the car 101 from the sending station by operation of the button 41. Energization of the up directional relay 3a again causes a starting up of the motor 1 by reason of the same cycle of operation previously carried thru and the car proceeds on its way.

Further rotation of the timing motor shaft carries contact 36d to the open position, and thereby causes de-energization of relay 84 and relay 85. De-energization of relay 85 thus produced closes contacts 85a, thereby completing circuit to relay 37 thru the path embracing contacts 42d, the latter having closed upon completion of the circuit thru lip-direction relay 3a just described. Energization of relay'37 thus produced causes opening of the circuit to the timing motor 35 at the switch 37 a, and as a result the motor 35 comes to rest. In the meantime the car proceeds until reaching the next unloading chute in succession, whereupon the same series of operations are automatically carried through, after which the car resumes its travel. The cycle is repeated for each unloading station until the car reaches its upper limit of travel, whereupon on again starting the motor 1 the direction of travel is re versed by reason of the fact that the circuit thru the segment 86 passes thru the down directional relay 2a rather than thru the up directional relay. The operation is similar on the downward trip, the segments on the commutator being arranged so that the car stops successively in proper alignment operation in the downward direction is as follows:

Although the solenoid controlling the movement of the car cam is operated for each landing just as in the upward trip, the resulting outward movement of the car cam does not cause a tilting of the shelves to the forward position for the reason that on the downward trip the car stops at points beyond the locations of the depending arms, as 143, and therefore, no kicking out of the shelf detent levers occurs. After making its stops at each of the loading chutes thecar proceeds to the sending station, the circuit to the audible signal 38 being completed just prior to the cars reaching its destination and the car slowing down and then stopping upon arrival at the sending station thru the operation of the slow down relay and the basement limit switch f? in a manner similar to that described previously in connection with the slowirx down and stopping upon arrival at the intermediate landings.

In the preferred form an additional feature to the operation on the final portion of the return trip is as follows Preferably adjacent the mechanical means provided for the operation of the basement limit switch there is also provided a latch or detent which is made to engage with the shaft door at the terminal station so as to lock the latter against opening movement while the car is away from the terminal station landing, such mechanical means being so arranged that the detent or latch is withdrawn from looking position by the physical presence of the car as it returns to the terminal station.

In this connection it might be observed that the shaft door at the controlling station preferably differs in construction from the shutters of the landing chutes in that it is desirable to provide a door of sufficient size to embrace all of the compartments of the car so that upon opening of this controlling station door all of the compartments of the car are made accessible, thereby facilitating removal of the contents of the car.

By reason of the fact that the return of the car deenergizes the relay 46 in the manner previously explained, the circuit to the timing motor 19 is opened at the contacts 46a on this occasion and consequently there is no operation of the timer as a result of the cars return to the terminal station. It may also be noted that the circuit to the audible signal 38d is broken at the switch 38a by reason of the de-energization of the relay 38, which in turn is brought about by the opening of the circuit theretoat the point 60, such opening taking place by reason of the opening of the shaft door at the controlling station. That is to say, the act of the attendant in opening the shaft door produces an open ing of the switch represented at 60, with the consequent opening of the audible signal circuit.

Also by reason of the de-energization of relay 46 a circuit is closed to the visual signal 90 passing thru the contacts 46d so as to indicate the presence of the car.

By way of further explanation of the preferred method of operating the shelves of the elevators it may be well to emphasize the fact that upon release of the detent levers, as 141, which positively hold the shelves in the backwardly tilted positions, the disposition of the contents of the shelves causes the shelf to tilt forwardly, thereby dumping the contents. Now, immediately following the dumping of the contents of the shelf, the shelf automatically returns to its backwardly tilted position, such return resulting by reason of the disposition of the center of gravity of the shelf or by suitable spring tension or by a combination of both of these factors In practice it has been found convenient to so weight the rear ends of the shelves that the gravity tends to return them to the backwardly tilted positions as soon as the contents are dumped.

The above specification and the annexed drawings are to be considered only as illustrative of what we deem the preferred embodiment at this time. The invention is not limited to this specific form or to any particular combination or application of the parts, but embraces all modified forms and constructions within the scope of the appended claims.

We claim:

1. in a control system for elevators, an elevator having a plurality of shelves, means for starting said elevator and stopping it successively at a plurality of predetermined landings, and means for loading a predetermined shelf in said elevator at each of said landings.

2. In a control system for elevators, an elevator having a plurality of shelves, means for starting said elevator and stopping it successively at a plurality of predetermined landings, and means for tilting and unloading a predetermined shelf in said elevator at each of said landings.

3. In a control system for elevators, an elevator having a plurality of shelves, a plurality of landings along the path of said elevator, means for causing said elevator to stop at said landings successively, automatic means for loading said shelves at certain of said landings, and means for unloading said shelves at other of said landings.

4t. In a control system for elevators, an elevator having a plurality of shelves, a plurality of landings along the path of said elevator, automatic means for causing said elevator to stop at and start away from each of said landings in a predetermined order, and means for tilting a selected one of said shelves at each of said landings.

5. In a control system for elevators, an elevat-or having a plurality of shelves, a plurality of landings along the path of said elevator, means for causing said elevator to stop and start away from said landings successively, and automatic means for loading a predetermined shelf in said elevator at each of said landings prior to the departure of the elevator from said landings.

6. In a control system for elevators, an elevator having a shelf, automatic means for hoisting said elevator and causing it to stop at a predetermined landing, electro-magnetically controlled means for tilting said shelf while the elevator is at said landing, and automatic means for causing said elevator to depart from said landing after the tilting of said shelf.

7. In a control system for elevators, an elevator having a plurality of shelves, automatic means for hoisting said elevator and causing it to stop at a predetermined landing, means for tilting one of said shelves when the elevator stops at said landing, and automatic means for causing said elevator to depart from said landing after the tilting of said shelf and stop at another landing, and means for tilting another of said shelves as said elevator stops at the latter landing.

8. In a control system for elevators, an elevator having a shelf, means for hoisting said elevator and causing it to stop at a predetermined landing, automatic means for tilting said shelf while the elevator is at said landing, automatic means for causing said elevator to depart from said landing after the tilting of said shelf, and means for rendering said hoisting means inoperative while said shelf is tilted from normal position.

9. In a control system for elevators, an elevator having a shelf, means for hoisting said elevator and causing it to stop at a predetermined landing, means for tilting said shelf while the elevator is at said landing, automatic means for causing said elevator to depart from said 'alanding after the tilting of said shelf, means for rendering said hoisting means inoperative while said shelf is tilted from normal position comprising an electric circuit, a switch in said circuit, and means for opening said switch as said shelf tilting means is operated.

10. As a sub-combination, a parcel elevator having a plurality of shelves normally disposed so as to tend to retain the contents in position thereon, mechanical detent means for holding each of said shelves in such position, means for selectively releasing said mechanical means to permit a forward tilting of certain of said shelves, thereby causing a July, A. D. 1928 g CYRUS W. BASSETT. HAROLD J. FEAR. 

